Reagent Tube and Stopper Assembly

ABSTRACT

A reagent tube and stopper assembly comprising in combination a cylindrical receptacle for containing a clot timing test reagent solution and a flexible stopper for closure thereof and dispensing a spherical member into said reagent solution by depressing a probe into an upper cavity in said stopper and against a thin membrane separating a lower sphere containing cavity in said stopper.

United States Patent 1191 1111 3,888,113

Miranda 1 1 June 10, 1975 i 1 REAGENT TUBE AND STOPPER 3,411,343 ll/l968Baird Jr. 73 57 ASSEMBLY 1635.678 i/l972 SCILZ 81 8|. 23/259 [75]inventor: Eduardo V. Miranda, Huntington FOREIGN PATENTS OR APPLICATIONSBeach, Calif. lUl 4()7 4/l94l Sweden 2l5/355 73 Assi nee: Baxt L bor t,l M t I g Grov e Hi 3 ones c or on Primary Examiner-R1chard C. QueisserAssistant Examiner-Joseph W. Roskos Fll6di ct. 3, 1973 Attorney, Agent,or Firm-Scott J. Meyer; Louis 21 Appl. No; 402,951 Altman 57 ABSTRACT[52] U.S. Cl. 73/641; 23/259; 23/292; s

73/57 A reagent tube and stopper assembly compnsmg in [51] Cl H Gm11/12, 60m 33/16 combination a cylindrical receptacle for containing a[58] Field of Search 73/64 k 57/33/259 292 clot timing test reagentsolution and a flexible stopper i 6 for closure thereof and dispensing aspherical member l into said reagent solution by depressing a probe into[56] References Cited an upper cavity in said stopper and against a thinmembrane separating a lower sphere containing cavity UNITED STATESPATENTS in Said Smpper 3,006,494 lU/l96l Reibeling 215/355 3,240 0533/1966 Jones 73 57 7 Claims 8 Drawing Flgum PATENTEDJUH 10 ms SHEET FIG.3.

SHEET PATENTEDJUH 10 1975 I REAGENT TUBE AND STOPPER ASSEMBLY Thisinvention relates to a reagent tube and stopper assembly and, moreparticularly, to a stoppered reagent tube for thromboplastin and partialthromboplastin products used in the determination of blood coagulationtimes.

The process of blood coagulation is a complex mechanism which involvesthe interaction of a number of blood components or factors. If there aredeficiencies in any of these components or defects in their interaction,the blood coagulation process may be altered such as to result in afailure to clot or prolongation of the clotting time.

Various tests have been devised for detecting and diagnosing bloodcoagulation defects and deficiencies. Among these tests are theprothrombin time determination tests such as the Quick l-stage test,Amer. J. Med. Sci. I90, 501 (I935 the modified Owren 2-stage testdescribed by Ware et al., Amer. J. Clin. Path. 22, 791 1952); and thepartial thromboplastin time (PTT) test described by Langdell et al., J.Lab. and Clin Med. 4i, 637 (I953).

The prothrombin time determination tests and PTT tests employ tissuethromboplastin and partial thromboplastin materials. These materials canbe obtained, for example, by extracting warm-blooded mammal brain tissuein accordance with the procedure described by Bell et al., Nature 174,880 (I954). In general, these tests are carried out by admixing a plasmasample with the thromboplastin or partial thromboplastin material andcalcium chloride, incubating at 37 C. and then measuring the time forclotting to occur. Further description of these tests and materials canbe found, for example, in U.S. Pat. Nos. 3,l79,567; 3,228,48l; 3,293,1343,395,2IO; 3,486,981; and 3,522,l48; and in Amer. J. Clin. Path. 57,482-6 (1972); 59, 58l-5 (I973).

Although these prothrombin time and PTT determination tests can becarried out manually, for mass testing purposes it is more desirable toconduct tests in automatic or semi-automatic equipment. Various types ofsuch equipment, generally referred to as clot timers, are known. Thesedevices determine the end point of the clotting by mechanical,electrical or similar such means.

One such recently developed clot timer determines the end point bysensing a change in viscosity of the sample. In this device, a magneticmember, such as a steel ball, is suspended within the fluid sample in areagent tube and a magnetic field is provided through the sample whichtends to hold the magnetic member in a fixed position as the sample isreciprocated. This condition obtains so long as the viscosity of thesample re mains below a predetermined threshold. However, when theincreased viscosity of the fluid sample is sufficient to enable thereciprocating fluid to move the steel ball away from its fixed position,and against the magnetic force tending to hold it in its fixed position,the change in the ball location in the sample is detected and theelapsed time is measured. Further description of this device can befound in U.S. Pat. No. 3,635,678.

In the latter described clot timing system, the reagent tube and thesteel ball are preferably very close in di ameter with only a smalltolerance existing between the ball and the inner wall of the tube. Inpractice, it is convenient to supply the reagent tube together with thesteel ball suspended in the thromboplastin or partial thromboplastinproduct. Due to the aforesaid small tolerance, there is a tendency ofundesirable cavitation reactions occurring and homogenization of thethrom boplastin material in the tube by the shaking which occurs inordinary handling and shipment.

Accordingly, it is an object of this invention to provide an improvedstoppered reagent tube for thromboplastin and partial thromboplastinproducts used in the determination of blood coagulation times.

Other objects and advantages of the invention will be apparent to theperson skilled in the art after reading the description hereof.

Briefly stated, the reagent tube and stopper assembly of this inventioncomprises a receptacle for containing a reagent solution and a flexiblestopper, said receptacle having a mouth and an elongated cylindricalwall, said flexible stopper having upper and lower surfaces, a generallycylindrical outer surface and upper and lower cavities, said lowercavity being generally spherical and having a downwardly disposedopening at said lower surface with a width less than the diameter ofsaid spherical cavity, said upper cavity having an upwardly disposedopening at said upper surface and being separated from said lower cavityby a thin, flexible membrane, said outer surface being adapted for snugpositioning within the inner cylindrical surface of the upper portion ofsaid receptacle, said spherical cavity being adapted for holding asphere having a diameter slightly less than the diameter of saidreceptacle.

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter regarded as forming thepresent invention, it is believed that the invention will be betterunderstood from the following exemplary description taken in connectionwith the accompanying drawings in which:

FIG. I is a perspective view of the reagent tube and stopper assembly ofthis invention.

FIG. 2 is a partial side elevational view of the reagent tube andstopper assembly in cross-section taken along the line 22 of FIG. 1.

FIG. 3 is another partial side elevational view of the reagent tube andstopper assembly in cross-section showing the operation of the device.

FIG. 4 is a top view of the reagent tube and stopper assembly.

FIG. 5 is a bottom view of the reagent tube and stopper assembly.

FIG. 6 is a partial side elevational view of another embodiment of thereagent tube and stopper assembly of this invention.

FIG. 7 is a top view of the reagent tube and stopper assembly of FIGv 6.

FIG. 8 is a bottom view of the reagent tube and stopper assembly of FIG.6.

Referring now to the drawings, particularly to FIGS. I to 5, the reagenttube and stopper assembly is generally indicated by 11 and comprisesreceptacle l2 and stopper 13. In this illustrative embodiment receptacle12 is a test tube having a mouth 14 at the top and elongated cylindricalwall 15. Receptacle 12 is adapted for containing a reagent solution 27.Receptacle 12 can be provided with a neck, if desired, for handlingpurposes, and it can also be provided with a lip, if desired, forpouring purposes. Receptacle 12 preferably is made of glass or a rigid,transparent plastic.

Stopper 13 is a combination closure and retaining device. It has agenerally cylindrical outer surface 18 whereby it is adapted for snugpositioning within the inner cylindrical surface of the upper portion ofreceptacle 12 for closure of mouth 14. As used herein, the term"generally cylindrical" includes cylindrical configurations andgradually inwardly tapering structures having a frusto-conicalconfiguration as illustrated in the drawings.

Stopper I3 is provided with two cavities. The lower cavity 21 isgenerally sperical and adapted for retaining a sphere, for example, asteel ball such as that described in the clot timing device of US. Pat.No. 3,635,678. In the clot timing method of said device it is desirableto employ a steel ball having a diameter only slightly less than thebore diameter of the reagent tube.

Lower cavity 21 has a downwardly disposed opening 23 with a neck 19 atthe lower surface 17 of stopper 13. The width of opening 23 is slightlyless than the diameter of cavity 21 so that sphere 26 retained thereinwill not fall into the lower portion of receptacle 12 without theapplication of an extrinsic force. However, opening 23 should besufficiently large so that upon the application of an extrinsic forcefrom above, the resiliency of the stopper will permit expansion of neck19 to the extent necessary to allow sphere 26 to be pushed out of cavity21.

Upper cavity is cylindrical in this illustrative embodiment and has anupwardly disposed opening 22 at the upper surface 16 of stopper I3.Separating cavities 20 and 21 is a relatively thin, flexible membrane24. Cavity 20 is adapted for placement therein of probe 25 which can bedepressed sufficiently downwardly to deform flexible membrane 24 andthereby serve as the extrinsic force to push sphere 26 out of lowercavity 21. Probe 25 can be any conveniently available laboratoryimplement, preferably elongated, such as a pipette tip, a small boretube or the end of a pencil.

Stopper 13 can be fabricated of a natural or synthetic rubber orelastomer or any flexible, resilient resinous plastic material such as,for example, vinyl, polyethylene or polypropylene plastics.

In the embodiment shown in FIGS. 6 to 8, receptacle 30 varies fromreceptacle 12 of the embodiment of FIGS. 1 to 5 primarily in that it islarger at the top portion than at the bottom portion in both its innerand outer diameters. Stopper is essentially similar to stopper 13 ofsaid embodiment of FIGS. 1 to 5. It has upper surface 36, lower surface41, upper cavity 37 and contains sphere in a correspondingly shapedlower cavity having opening 39.

In this embodiment of FIGS. 6 to 8, receptacle 30 is provided with anouter circumferentially disposed retaining collar 31 whereby the outerdiameter of the upper portion of receptacle 30 is greater than the outerdiameter of its lower cylincrical wall 32. Receptacle 30 is therebyadapted for placement and retention in a suitable clot timing apparatussuch as described, for example, in US. Pat. No. 3,635,678. Inparticular, when receptacle 30 is fabricated of a lightweight plasticmaterial, retaining collar 31 provides a desirable additional weight tothe receptacle for improved seating during the vertical reciprocatingmotion of the clot timing test in said apparatus.

In the latter embodiment, the inner diameter of receptacle 30 is greaterat upper portion 33 where stopper 35 is inserted than at the lowerportion 34 where the clot timing reaction takes place. This enlargeddiameter is adapted to accommodate a thickness of stopper 35 at its neck38 such that a desired slight tolerance can be maintained between sphere40 and the inner wall of receptacle 30 at lower portion 34 as saidsphere 40 is pushed downwardly in said receptacle by a probe inserted incavity 37.

In the operation of the device of this invention, as can best be seenfrom FIGS. 2 and 3, sphere 26 will be retained in cavity 21 whilestopper I3 is in the closed position in receptacle l2 and prior to theinitiating of the clot timing reaction. At such time as the operator isready to begin the clot timing test, without necessity of removing thestopper l3, probe 25 will be inserted in cavity 20 and gently depressedagainst membrane 24 to force sphere 26 out of cavity 21 and into fluidsample 27 contained in receptacle 12. The remaining steps of the clottiming test are then carried out in the conventional manner.

In an illustrative example of the invention, receptacle 12 is a one ml.size glass test tube with a bore diameter of about 022 inch. It isprefilled with about 0.1 ml. liquid thromboplastin. Rubber stopper 13has a height of about 0.45 inch, an upper surface diameter of about0.315 inch and a lower surface diameter of about 0.22 inch. Cavity 20has a cylindrical configuration about 0.125 inch in diameter and about0.23 inch in height. Cavity 21 has a spherical configuration about 0.187inch in diameter with its center being about 0.09 inch perpendicularlyabove the center of lower surface 23. Lower surface 23 has a centrallydisposed opening having a diameter about 0. l6 inch and a neck about0.047 inch in height.

In another example of the invention, illustrating the embodiment shownin FIGS. 6 to 8, receptacle 30 is a 1 ml. size plastic test tube with abore diameter at upper portion 33 of about 0.25 inch and a bore diameterat the lower portion 34 of about 0.198 inch. Sphere 40 retained instopper 35 has a diameter of about 0.187 inch and thereby a slighttolerance is maintained between said sphere and the inner wall ofreceptacle 30 at lower portion 34 as it is pushed into the receptacle.In this example, receptacle 30 also has a circumferentially disposedretaining collar 31 about 0.6 inch high and about 0.43 inch in diameter.In other respects, the reagent tube and stopper assembly in this exampleis similar to that of the previous example set forth above.

It will be appreciated, of course, that the specific dimensions setforth in the foregoing examples are not to be taken as limiting theinvention but are provided for exemplary purposes in describing theinvention.

While particular embodiments of the invention have been illustrated anddescribed, it will be obvious to those skilled in the art that variouschanges and modifications can be made without departing from the spiritand scope of the invention, and it is intended to cover in the appendedclaims all such changes and modifications.

What is claimed is:

l. A reagent tube and stopper assembly comprising in combination areceptacle for containing a reagent solution and a flexible stopper forclosure thereof and dispensing a spherical member into said reagentsolution, said receptacle having a mouth and an elongated cylindricalwall, said flexible stopper having upper and lower surfaces, a generallycylindrical outer surface and upper and lower cavities, said lowercavity being generally spherical and having a downwardly disposedopening at said lower surface with a width less than the diameter ofsaid spherical cavity, said upper cavity having an upwardly disposedopening at said upper surface and being separated from said lower cavityby a thin, flexible membrane, said outer surface being adapted for snugpositioning within the inner cylindrical surface of the upper portion ofsaid receptacle. said spherical cavity being adapted for holding asphere having a diameter slightly less than the diameter of saidreceptacle.

2. The reagent tube and stopper assembly of claim 1 in which a magneticsphere is retained within said lower spherical cavity.

3. The reagent tube and stopper assembly of claim 1 in which thediameter of the upper portion of said receptacle is greater than thediameter of the lower portion of said receptacle.

4. The reagent tube and stopper assembly of claim 1 in which saidreceptacle is provided with an outer circumferentially disposedretaining collar at the upper portion.

5. The reagent tube and stopper assembly of claim 1 in which thediameter of the upper portion of said receptacle is greater than thediameter of the lower portion of said receptacle and in which saidreceptacle is provided with an outer circumferentially disposedretaining collar at said upper portion.

6. The reagent tube and stopper assembly of claim 5 in which a magneticsphere is retained within said lower spherical cavity.

7. A method of initiating a magnetically sensed clot timing testreaction comprising placing a magnetic sphere in the lower cavity of aflexible stopper having upper and lower surfaces, a generallycylindrical outer surface and upper and lower cavities, said lowercavity being generally spherical and having a downwardly disposedopening at said lower surface with a width less than the diameter ofsaid spherical cavity, said upper cavity having an upwardly disposedopening at said upper surface and being separated from said lower cavityby a thin, flexible membrane, closing a cylindrical receptacle with saidstopper, depressing a probe in the upper cavity of said stopper andagainst said membrane whereby said sphere is pushed out of said lowercavity and into the lower portion of said receptacle.

1. A reagent tube and stopper assembly comprising in combination areceptacle for containing a reagent solution and a flexible stopper forclosure thereof and dispensing a spherical member into said reagentsolution, said receptacle having a mouth and an elongated cylindricalwall, said flexible stopper having upper and lower surfaces, a generallycylindrical outer surface and upper and lower cavities, said lowercavity being generally spherical and having a downwardly disposedopening at said lower surface with a width less than the diameter ofsaid spherical cavity, said upper cavity having an upwardly disposedopening at said upper surface and being separated from said lower cavityby a thin, flexible membrane, said outer surface being adapted for snugpositioning within the inner cylindrical surface of the upper portion ofsaid receptacle, said spherical cavity being adapted for holding asphere having a diameter slightly less than the diameter of saidreceptacle.
 2. The reagent tube and stopper assembly of claim 1 in whicha magnetic sphere is retained within said lower spherical cavity.
 3. Thereagent tube and stopper assembly of claim 1 in which the diameter ofthe upper portion of said receptacle is greater than the diameter of thelower portion of said receptacle.
 4. The reagent tube and stopperassembly of claim 1 in which said receptacle is provided with an outercircumferentially disposed retaining collar at the upper portion.
 5. Thereagent tube and stopper assembly of cLaim 1 in which the diameter ofthe upper portion of said receptacle is greater than the diameter of thelower portion of said receptacle and in which said receptacle isprovided with an outer circumferentially disposed retaining collar atsaid upper portion.
 6. The reagent tube and stopper assembly of claim 5in which a magnetic sphere is retained within said lower sphericalcavity.
 7. A method of initiating a magnetically sensed clot timing testreaction comprising placing a magnetic sphere in the lower cavity of aflexible stopper having upper and lower surfaces, a generallycylindrical outer surface and upper and lower cavities, said lowercavity being generally spherical and having a downwardly disposedopening at said lower surface with a width less than the diameter ofsaid spherical cavity, said upper cavity having an upwardly disposedopening at said upper surface and being separated from said lower cavityby a thin, flexible membrane, closing a cylindrical receptacle with saidstopper, depressing a probe in the upper cavity of said stopper andagainst said membrane whereby said sphere is pushed out of said lowercavity and into the lower portion of said receptacle.